It's likely you've heard the story about a young man who used Google Earth to find the Indian village he went missing from as a five-year-old boy. Saroo Brierley turned his remarkable journey home into a book, A Long Way Home, and, given it's the kind of story that sounds too good to be true, it's no surprise the story is now a film.

Don't let already knowing the basics of Saroo's story stop you seeing this film. It's a complex story of identity, family, resilience and reconciliation and, unless you've read the book, there are more revelations than expected.

Lion comes in two distinctive parts: Saroo as a 5-year-old in India in 1986, and later as an adult in Australia in 2008.

The first part is harrowing, with Saroo taking refuge on a train one night only to wake up and find he's travelling 1600km across India to Kolkata. Once there, Saroo lives on the street, regularly dodging adults with unpleasant intentions. The tension and tragedy of the situation becomes almost unbearable, until Saroo is placed in an orphanage, from which he's adopted by a loving couple from Tasmania, John and Sue Brierley (Wenham and Kidman).

Sunny Pawar plays a young Saroo Brierley in Lion.
Sunny Pawar plays a young Saroo Brierley in Lion.

The second part begins two decades later when Saroo, a self-assured, charming Australian-ised young man, meets other Australian-Indians and realises he has no idea where he's from or who he is. Encouraged by his girlfriend (Rooney Mara), he begins the impossible task, via Google Earth, of trying to remember anything he can about his childhood that may lead him home to his family.

Given he doesn't know the name of his mother or village, it's a daunting task, and one that begins to overwhelm him. As determined to find his biological mother and siblings as he is to not upset his Australian parents, he retreats from the world and those around him.

The story is at first driven by an incredible performance by Sunny Pawar, who instinctively captures the emotions you expect from a child realising he may never see his family again. But it also encompasses broader issues such as child trafficking and labour, and poverty, which makes for a more nerve-wracking ride than what follows later.

A focused Dev Patel also puts in a great performance as the adult Saroo, although his journey is more internal and introverted, and somewhat slows the story momentum. Both parts are livened up by Nicole Kidman's wigs, which threaten to overshadow an otherwise captivating performance. The 80s were not kind to hair.

There may be two tonally different stories, but Australian director Garth Davis (co-director of Top of the Lake) uses this device to highlight the vast difference between Saroo's two families and how one simple decision can drastically change a life. All this adds to the emotional punch of the film.

Yes, Lion may be an uplifting story of one man's determination and hope, a story of compassion and the importance of being connected, but it's one heck of a fraught ride getting there. Don't think about stepping into the theatre without a good supply of tissues.

Cast: Dev Patel, Nicole Kidman, David Wenham
Director: Garth Davis
Running Time: 118 mins
Rating: PG
Verdict: A remarkable story well told, and great advert for Google Earth.